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PubMed1998

Potential for routine concurrent determination of chlamydia and cervical abnormalities by single fluid-based sampling.

Objective: The FDA recently approved adjunctive HPV testing from the vial of PreservCyt(R) Solution used for the ThinPrep(R) Pap Test. We have now evaluated the potential for routine chlamydia testing from cellular material collected for primary Pap testing using the fluid-based ThinPrep method.Methods: Cervical scrapings were collected for a conventional Pap smear and residual material adhering to the sampling implement after slide preparation was suspended in PreservCyt Solution. Chlamydia testing was performed on this residual material using two methods. 1) A slide was prepared using the ThinPrep 2000 System for a determination by direct fluorescence. 2) One mL of the cell suspension was removed and processed for determination by an amplified DNA probe technique. A separate conventional endocervical swab sampling from the same patient was used for testing by an independent direct DNA probe technique (reference method). One hundred specimens were selected and intentionally biased, 19 positive and 81 negative based on the independent swab results, for comparison to the slide and amplified DNA probe methods.Results: The slide-based method gave a sensitivity of 84% (16/19) and a specificity of 100% (81/81). Of 3 discrepant specimens, 2 tested positive by the amplified probe method, while all 3 remained negative by repeat DFA. The amplified probe method gave a sensitivity of 95% (18/19) and a specificity of 99% (80/81) after analysis of discrepant samples by repeat testing.Conclusions: Feasibility has been demonstrated for accurate and effective routine testing for chlamydia with either DFA or DNA probe methods, from a single, fluid-based sample already approved for primary Pap screening.

Journal Article↗
PubMed2002

[Abortion in cattle caused by Chlamydia psittaci].

A case of bovine abortion was for the first time in Switzerland diagnosed by immunohistochemistry PCR (16S rRNA, ompA) and gene sequence analysis to be caused by Chlamydia psittaci. A possible occurence of further cases has to be investigated. Based on the existence of several methods with very different sensitivity and specificity to diagnose chlamydia it is suggested that at least two verified diagnostic tools should be used to diagnose an involvement of chlamydia in bovine abortion.

Abortion, Veterinary↗
PubMed1998

Tandem genes of Chlamydia psittaci that encode proteins localized to the inclusion membrane.

Chlamydiae are obligate intracellular bacteria that replicate within a non-acidified vacuole, termed an inclusion. To identify chlamydial proteins that are unique to the intracellular phase of the life cycle, a lambda expression library of Chlamydia psittaci DNA was differentially screened with convalescent antisera from infected guinea pigs and antisera directed at formalin-fixed purified chlamydial elementary bodies (EBs). One library clone was identified that harboured two open reading frames (ORFs) with coding potential for similar-sized proteins of approximately 20 kDa. These proteins were subsequently termed IncB and IncC. Sequencing of the cloned insert revealed a strong Escherichia coli-like promoter sequence immediately upstream of incB and a 36nt intergenic region between the ORFs. Sequence analysis of the region upstream of incB and incC revealed two ORFs that had strong homologies to an amino acid transporter and a sodium-dependent transporter. Immunoblotting with antisera directed at IncB or IncC demonstrated that these proteins are present in C. psittaci-infected HeLa cells but are absent or below the level of detection in purified EBs. Reverse transcriptase-polymerase chain reactions provided evidence that incB and incC are transcribed in an operon. Immunofluorescence microscopy demonstrated that IncB and IncC are each localized to the inclusion membrane of infected cells. No primary sequence similarity is evident between IncA, IncB or IncC, but each contains a large hydrophobic domain of similar size and character as in IncA. Analysis of the recently completed C. trachomatis serovar D genome database has revealed C. trachomatis ORFs encoding homologues to incB and incC, indicating that these genes are conserved among the chlamydiae.

Animals↗
PubMed2001

Secretion of predicted Inc proteins of Chlamydia pneumoniae by a heterologous type III machinery.

Chlamydia spp. are strictly intracellular pathogens that grow inside a vacuole, called an inclusion. They possess genes encoding proteins homologous to components of type III secretion machineries, which, in other bacterial pathogens, are involved in delivery of bacterial proteins within or through the membrane of eukaryotic host cells. Inc proteins are chlamydial proteins that are associated with the inclusion membrane and are characterized by the presence of a large hydrophobic domain in their amino acid sequence. To investigate whether Inc proteins and other proteins exhibiting a similar hydropathic profile might be secreted by a type III system, we used a heterologous secretion system. Chimeras were constructed by fusing the N-terminal part of these proteins with a reporter, the Cya protein of Bordetella pertussis, and these were expressed in various strains of Shigella flexneri. We demonstrate that these hybrid proteins are secreted by the type III secretion system of S. flexneri, thereby providing evidence that IncA, IncB and IncC are secreted by a type III mechanism in chlamydiae. Moreover, we show that three other proteins from Chlamydia pneumoniae, all of which have in common the presence of a large hydrophobic domain, are also secreted by S. flexneri type III secretion machinery.

Adenylyl Cyclases↗
PubMed1999

[Chlamydia pneumoniae in coronary plaques: Increased detection with acute coronary syndrome].

BACKGROUND AND OBJECTIVE: There is seroepidemiologic and experimental evidence for a link between Chlamydia (C.) pneumoniae and arteriosclerosis. However, the clinical importance and the pathogenic pathways implicated remain unclear. In the present study, we sought to evaluate the presence and the location of C. pneumoniae in coronary atheroma, as well as a potential prevalence with unstable versus stable angina. PATIENTS AND METHODS: Retrospectively, coronary plaque material of primary lesions from 51 consecutive patients (44 men, 7 women, mean age 59.6 +/- 9.4 years) was examined for the presence of C. pneumoniae by use of immuno-histochemistry and transmission electron microscopy. The findings associated with clinically acute coronary syndrome according to Braunwald's classification (n = 31) were compared to those with stable angina (n = 20) and regarded for potential relations to characteristic intimal features. RESULTS: Immunoreaction for C. pneumoniae was found in 32 of 51 (63%) coronary plaques. Signals (% prevalence of specific intimal features) were present with necrotic areas (40%), sparse cellularity (40%), neo-vascularization (29%), thrombi (20%), ruptured plaque areas (19%), and fields rich in foam cells and calcifications (13%). Intimal hyperplasia and inflammatory infiltrates showed no signals. As the central finding in this report, C. pneumoniae immunoreaction was more frequently (P < 0.001) found in 26 of 31 (84%) lesions associated with unstable angina or acute myocardial infarction, compared to 6 of 20 (30%) lesions with stable angina (P < 0.001). Intact vessels devoid of arteriosclerotic disease, such as mammarial arteries and saphenous veins, were without C. pneumoniae signals (negative controls). Ultrastructurally, chlamydial elementary bodies were found in foam cells and phagocytosing macrophages, also in fragmented extracellular matrix adjacent to apoptotic and necrotic intimal cells. CONCLUSIONS: Chlamydiae pneumoniae were detected in 32 of 51 (63%) coronary primary lesions of symptomatic patients. Most importantly, there was a highly significant prevalence of lesions associated with acute coronary syndrome. Predilection sites of C. pneumoniae were areas that revealed small healing activity and (or) propensity to plaque rupture. The present in situ findings indicate a pathogenic role of Chlamydiae pneumoniae in human (coronary) plaque rupture.

Aged↗
PubMed2003

Macrophage L-type Ca2+ channel antagonists alter Chlamydia pneumoniae MOMP and HSP-60 mRNA gene expression, and improve antibiotic susceptibility.

Recent data have shown a unique relationship between Ca2+ signaling in macrophages through L-type channels and the outcome of C. pneumoniae infection of such cells. The present investigation seeks to provide insights into the manner in which macrophage L-type Ca2+ channel operation affects major outer membrane protein (MOMP) and heat shock protein-60 (HSP-60) mRNA gene expression (factors associated with Chlamydia chronicity), and the possible effect of this on antibiotic susceptibility. Intracellular calcium ([Ca2+]i) chelation using varying doses of 1,2-bis (o-aminophenoxy) ethane-N,N,N'N'--tetra acetic acid (acetoxymethyl) ester (BAPTA-AM) induced an increase in MOMP and a decrease in HSP-60 mRNA gene expression. L-type Ca2+ channel antagonists produced an identical but enhanced effect. Since these findings associate specialized Ca2+ channels to Chlamydia chronicity, it was important to determine Ca2+ channel effect on the usual antibiotic refractory form of C. pneumoniae in macrophages. Inhibition of macrophage L-type Ca2+ channel operation improved C. pneumoniae antibiotic susceptibility assessed by decreased inclusion counts or down-regulated MOMP and HSP-60 mRNA gene expression. These findings provide molecular insights into how specialized Ca2+ channels influence Chlamydia chronic course in macrophages and demonstrates a role for L-type Ca2+ channel inhibitors in enhanced C. pneumoniae susceptibility to antibiotic therapy.

Animals↗
PubMed2002

Chlamydia pneumoniae and atherosclerosis.

Chlamydia pneumoniae, a human respiratory pathogen, has been linked to atherosclerotic disease based on sero-epidemiologic studies, direct detection of the organism in atherosclerotic lesions, animal experiments and tissue culture. In this review paper we propose to interpret results in line with the biology of Chlamydia with persistence of Chlamydia pneumoniae antigens in the pathogenesis of atherosclerosis rather than viable bacteriae.

Adolescent↗
PubMed1999

A prospective study of asymptomatic Chlamydia trachomatis in Barbadian women.

A prospective study to determine the prevalence of asymptomatic female genital tract Chlamydia trachomatis infection was performed on 167 women at the Queen Elizabeth Hospital, Barbados, West Indies and at a private clinic. The ELISA (Microtrak, chlamydia EIA, Syva, CA) method was used to detect Chlamydia trachomatis antigen. Nineteen (11.4% 95% CI 6.5-16.3) women were found positive. The efficacy of a single 1 gram dose of azithromycin given orally to 18 patients was tested after 4 weeks. One patient who was pregnant was given 500 mg erythromycin four times daily orally for 1 week. Only six patients (including the pregnant patient) reported for follow up. All six repeat swabs were negative for C. trachomatis antigen. The prevalence of 11.4% asymptomatic chlamydial infection in endocervical swabs in Barbadian women is in agreement with a previous study which reported a prevalence of 18.4% +/7.8%. Patient compliance was assured, using a single dose of azithromycin. It was found to be as effective as doxycyline and ciprofloxacin as reported by other workers.

Journal Article↗
PubMed1995

Molecular identification of an avian strain of Chlamydia psittaci causing severe keratoconjunctivitis in a bird fancier.

A healthy female bird fancier developed progressive follicular keratoconjunctivitis despite topical treatment with antibiotics and steroids. Although bacterial, viral, and chlamydial cultures were negative, direct fluorescent antibody staining of conjunctival scrapings revealed chlamydial lipopolysaccharide; however, this procedure failed to detect the major outer membrane protein (MOMP) of Chlamydia trachomatis. The polymerase chain reaction (PCR) used with species-specific primers to the MOMP gene detected DNA of Chlamydia psittaci. Genotype analysis of the infecting strain revealed a nucleotide homology of 96% with C. psittaci avian strain 6-BC. Serum IgG titers were measured at 1:512 by microimmunofluorescence at 6 weeks, and they remained elevated for 3 months. A 10-week course of treatment with doxycycline was required for eradication of the infection. This case illustrates the importance of PCR/genotyping for direct detection and typing of Chlamydia species when chlamydial infections are suspected. To our knowledge, this is the first report of a naturally occurring ocular infection due to an avian strain of C. psittaci.

Amino Acid Sequence↗
PubMed2004

Abnormal pap smears in teenage mothers and the association with domestic violence, homelessness, and Chlamydia.

OBJECTIVE: To assess the incidence of Pap smear abnormalities and cervical intraepithelial neoplasia (CIN) on cervical biopsy results in teenage mothers and to establish if there are associations with social disruption. PATIENTS AND METHODS: A prospective study of 498 pregnant teenagers was performed at three Australian hospitals. Enrolled patients had a Pap smear performed. Women with abnormal Pap smear results underwent colposcopy with directed biopsy of the cervix. Independently, women were interviewed to identify demographic and social variables. Variables associated with an abnormal Pap smear result were analyzed using a mixed model of analysis. RESULTS: Four hundred fifty-seven patients participated in the study (response rate, 92%). The prevalences of low- and high-grade squamous intraepithelial lesions on Pap smear were 37 in 1,000 and 13 in 1,000, respectively. The prevalence of CIN 1 was 35 in 1,000 and of CIN 2,3 was 15 in 1,000. In univariate analysis, teenagers with abnormal Pap smear results were significantly more likely to have a history of exposure to domestic violence (odds ration [OR], 7.10; 95% CI, 2.76-18.53), be homeless (OR, 6.82; 95% CI, 2.59-17.83), to have coexisting Chlamydia infection (OR, 5.44; 95% CI, 1.59-17.64), or be current users of illegal drugs or have a history of illegal drug use (current: OR, 3.06; 95% CI, 1.22-7.69; history: OR, 2.75; 95% CI, 1.04-7.53). Exposure to domestic violence, homelessness, and Chlamydia infection remained significant on multivariate analysis (p < .05). CONCLUSIONS: The incidence of CIN in pregnant teenagers is high and is associated with domestic violence, homelessness, and Chlamydia infection.

Journal Article↗
PubMed1996

Development of a simplified polymerase chain reaction-enzyme immunoassay for the detection of Chlamydia pneumoniae.

The 16S rRNA genes of two Chlamydia pneumoniae and two C. psittaci strains of different serovars were sequenced then compared to previously reported Chlamydia 16S rRNA gene sequences. Chlamydia pneumoniae-specific regions were identified and specific primers for nested PCR were synthesized. Nested PCR reactions were performed, in a single tube, by varying the annealing temperature of the amplification cycles. The initial thermal cycles were selected to allow annealing and extension of only the outer primer pair, whilst in later cycles a temperature that allowed inner primer annealing was employed. The inner primers were labelled, one with biotin and the other with fluorescein and consequently the dual labelled amplicon could be immobilized onto antibiotin-coated microtitre plates and detected colorimetrically via an antifluorescein-enzyme conjugate. The assay was found to be sensitive and specific. No cross reactions were observed with C. trachomatis, C. psittaci or other common respiratory pathogens.

Chlamydophila pneumoniae↗
PubMed2004

Tryptophan recycling is responsible for the interferon-gamma resistance of Chlamydia psittaci GPIC in indoleamine dioxygenase-expressing host cells.

Comparative genomics indicates that vast differences in Chlamydia sp. host range and disease characteristics can be traced back to subtle variations in gene content within a region of the chromosome termed the plasticity zone. Genes required for tryptophan biosynthesis are located in the plasticity zone; however, the complement of genes encoded varies depending on the chlamydial species examined. Of the sequenced chlamydia genomes, Chlamydia psittaci GPIC contains the most complete tryptophan biosynthesis operon, encoding trpRDCFBA. Immediately downstream of the trp operon are genes encoding kynureninase and ribose phosphate pyrophosphokinase. Here, we show that, in GPIC, these genes are transcribed as a single transcript, the expression of which is regulated by tryptophan. Complementation analyses, using various mutant Escherichia coli isolates, indicate that the tryptophan biosynthesis, kynureninase and ribose phosphate pyrophosphokinase gene products are functional. Furthermore, growth of C. psittaci GPIC in HeLa cells, cultured in tryptophan-free medium, could be rescued by the addition of anthranilate, kynurenine or indole. In total, our results indicate that this complement of genes enables GPIC to recycle tryptophan and thus accounts for the interferon-gamma resistant phenotype displayed in indoleamine-2,3-dioxygenase-expressing host cells.

Amino Acid Sequence↗
PubMed1996

Clinical features of Chlamydia pneumoniae acute respiratory infection.

Chlamydia pneumoniae is a worldwide respiratory pathogen involved in 6--20% of community-acquired pneumonias and in about 5% of acute exacerbations of chronic bronchitis. Preliminary data also indicate a possible association between Chlamydia pneumoniae infection and asthma. Further studies are needed to elucidate whether Chlamydia pneumoniae is merely a precipitant of asthma symptoms or is actually one of the causes of asthma.

Journal Article↗
PubMed1997

Multicenter comparative evaluation of two rapid immunoassay methods for the detection of Chlamydia trachomatis antigen in endocervical specimens.

OBJECTIVE: To evaluate two rapid immunoassay methods, QuickVue-Chlamydia (Quidel Corp., San Diego California) and Kodak SureCell (Kodak Corp., Rochester, NY) for the detection of Chlamydia trachomatis antigen in endocervical swabs from high- and low-risk females. METHODS: Seven hundred and twenty-four females attending three clinics were enrolled in the study. The results were compared to McCoy's or BGMK cell culture and discrepancies resolved with polymerase chain reaction and direct fluorescent antibody tests performed on left-over culture specimens. RESULTS: The sensitivity, specificity, predictive value of a positive and predictive value of a negative of the QuickVue Chlamydia assay were 92.0%, 99.1%, 92.0% and 99.1%, respectively. The sensitivity, specificity, predictive value of a positive and predictive value of a negative of the SureCell assay were 90.0%, 99.8%, 98.6% and 98.8%, respectively. CONCLUSIONS: The performances of the two immunoassay methods were similar, and slight differences in sensitivity and specificity were not statistically significant. Both immunoassay methods performed well in high- and low-risk patient groups, both for symptomatic and for asymptomatic patients.

Journal Article↗
PubMed1978

Chlamydia psittaci infection in Danish cattle.

Intestinal tract infection by Chlamydia psittaci was demonstrated in one cattle herd by isolation from faecal specimens, using embryonated eggs. Such infections were observed in all animals younger than 12 months, in 60% of the heifers and in none of the adult cows. The presence of infection correlated (r=0.511) with the serum titre of compliment fixation antibodies against chlamydial antigen. Young calves, which were spontaneously infected with Chlamydia postnatally, developed ileitis and moderate interstitial pneumonia. The results of histological sections and isolation of the agent from tissue specimens indicated Chlamydia to be the cause of these conditions. The strain isolated (ROS DK/KVL 6/B3) was identified as C. psittaci. The morphology of the organism and it's pathogenicity in guinea-pigs were studied. In embryonated eggs, a dose-response curve was demonstrated for the ROS strain, which differed in that respect from another member of this species tested, viz. EBA (59-795).

Animals↗
PubMed1987

The effect of intracellular Chlamydia psittaci on lysosomal enzyme activities in mouse peritoneal macrophages.

Live or heat killed (30 min at 56 degrees C) Chlamydia psittaci elementary bodies (EB) were phagocytosed by mouse peritoneal macrophages. Inoculation with killed Chlamydia caused rises in three lysosomal enzyme activities tested, especially in acid phosphatase activity. In contrast, after infection with live Chlamydia, only a negligible increase was seen in acid phosphatase activity, and no change in the activities of beta-glucuronidase and cathepsin D was observed. It was concluded that regulation of lysosomal enzyme synthesis in macrophages may be linked to signals mediated by phago-lysosome fusions.

Acid Phosphatase↗
PubMed1997

Comparison of the omp I gene of Chlamydia psittaci between isolates in Victorian koalas and other animal species.

OBJECTIVE: The objective of this study is to compare the strain of chlamydia causing genital infection in koalas from Victoria with isolates from other animal species. DESIGN: Polymerase chain reaction and restriction enzyme analysis has been used to compare various Chlamydia psittaci isolates from a range of animals and disease syndromes. The isolates used in this study include isolates from three birds, three from aborted sheep, one from polyarthritis, one from bovine abortion, one from feline pneumonitis, three porcine isolates from faeces, polyarthritis and abortion, and three urogenital isolates from Victorian koalas. PROCEDURE: Two polymerase chain reactions were performed, each amplifying a different region of the omp 1 gene. The first polymerase chain reaction amplified a 144 bp segment of the gene which was then digested with the restriction enzyme EcoR I. The second polymerase chain reaction amplified a larger 1070 bp region of the omp 1 gene which was digested with two restriction enzymes Alu I and Nde II. RESULTS AND CONCLUSIONS: The results obtained have confirmed that variation in DNA sequence of various animal chlamydia isolates does occur. They have also shown that it is possible to classify isolates, based on their restriction enzyme profiles, into distinct groups.

Animals↗
PubMed1978

Chlamydia psittaci infection of horses with respiratory disease.

Two strains of Chlamydia psittaci were isolated from the nasal tract of horses with acute respiratory disease. These 2 isolates (NS 121 and NS 172) were characterized as chlamydia on the basis of their morphology, tinctorial property, growth in chicken embryos, inability to grow on bacterial media and their possession of chlamydial common complement fixing group antigen. They were identified as C. psittaci on the basis of resistance to sodium sulphadiazine. The present strains were not pathogenic to mice and guinea pigs and non-toxigenic. They induced antibodies and caused latent infection in mice and guinea pigs. Acute and convalescent sera were avaliable from one of the horses and rising levels of specific antibody were demonstrated. No chlamydia were isolated from the materials of 14 aborted foals, 4 synovial fluids from horses with acute polyarthritis and nasal, tracheal and lung material from another 276 horses.

Animals↗